方程式

Consider equations having the following form: a*x1*x1 + b*x2*x2 + c*x3*x3 + d*x4*x4 = 0 a, b, c, d are integers from the interval [-50,50] and any of them cannot be 0. It is consider a solution a system ( x1,x2,x3,x4 ) that verifies the equation, xi is an integer from [-100,100] and xi != 0, any i ∈{1,2,3,4}. Determine how many solutions satisfy the given equation.

输入

The input consists of several test cases. Each test case consists of a single line containing the 4 coefficients a, b, c, d, separated by one or more blanks.

输出

or each test case, output a single line containing the number of the solutions.

样例输入

1 2 3 -4
1 1 1 1

样例输出

39088
0

#include<iostream>
 #include<cstring>
 using namespace std;
 int f1[1000005];
 int f2[1000005];
 int main()
 {
     long long int  a,b,c,d,sum,i,j,k;
     while(cin>>a>>b>>c>>d)
     {
         if(a>0 && b>0 && c>0 && d>0||a<0 && b<0 && c<0 && d<0)
         {
         cout<<0<<endl;
         continue;
         }
         memset(f1,0,sizeof(f1));
         memset(f2,0,sizeof(f2));
         for(i=1;i<=100;i++)
         {    for(j=1;j<=100;j++)
             {
                k=a*i*i+b*j*j;
                if(k>=0) f1[k]++;
                else f2[-k]++;
             }
         }
         sum=0;
         for(i=1;i<=100;i++)
         {
             for(j=1;j<=100;j++)
             {
               k=c*i*i+d*j*j;
               if(k>0) sum+=f2[k];
               else sum+=f1[-k];
             }
         }
         sum=sum*16;
         cout<<sum<<endl;
     }
    return 0;
 }